Cupping/scalloping is caused by a combination of the tyre compound and tread pattern. For example, between two grooves, the leading edge of the tread squirms more than the trailing edge of the tread at the following groove. This causes a wavy but regular wear pattern around the tyre ... scalloping ... commonly called cupping, but cupping is actually something different (concave pockets worn into the tread). A softer tyre will squirm more than a harder tyre and a deeper groove will allow more tread movement than a shallow groove. Tyre profile, inflation and suspension behaviour also come into play. Under hard use, all treaded tyres will eventually display some degree of "cupping" .... depending on the tread and compound combination this will be barely noticeable on some tyres and quite dramatic on others. A tyre that "cups" badly (like a BT010) will have a limited life span since the "cupping" will force a tyre change while there's still useable tread on the tyre. The best street tyres are those that stick like glue but don't have to be retired early because of "cupping. If your tyres "cup" badly, replace then with a different brand/model until you get a tyre that you're happy with.
irate